1. Field of the Invention
The described embodiments relate generally to portable computing devices. More particularly, the present embodiments relate to display housings for portable computing devices.
2. Description of the Related Art
A design of a portable computing device can involve complex tradeoffs. A few factors that can be considered in the design process are cosmetic appeal, weight, manufacturability, durability, thermal compatibility and power consumption. A component that is selected on the basis of its positive contribution to one of these design factors can have an adverse impact on one of more other design factors.
One design challenge associated with the portable computing device is the design of the enclosures used to house the various internal components. This design challenge generally arises from a number conflicting design goals that includes the desirability of making the enclosure lighter and thinner, the desirability of making the enclosure stronger and making the enclosure more esthetically pleasing. The lighter enclosures, which typically use thinner plastic structures and fewer fasteners, tend to be more flexible and therefore they have a greater propensity to buckle and bow when used while the stronger and more rigid enclosures, which typically use thicker plastic structures and more fasteners, tend to be thicker and carry more weight. Unfortunately, increased weight can lead to user dissatisfaction while bowing can damage the internal parts. Thus, materials are selected to provide sufficient structural rigidity while meeting weight constraints and providing necessary aesthetic appeal.
Deformation of an enclosure, such as bowing, can result from mechanical loads externally applied to the enclosure. For example, a user can sit-on, step-on or drop the portable computing device which, in each instance, introduces a unique set of mechanical loads that can result in deformation of the enclosure and possibly damage the internal components. Besides mechanical loads, the portable computing device can also experience thermal loads that can result in deformation of the enclosure.
During operation of a portable computing device, the device can experience a range of temperatures. For example, a device left in a car over-night, depending on the location and time of year, can experience temperatures well below freezing. Further, a device left in a car during the day can experience temperatures as high as 65 degrees Celsius. Because of mismatches in thermal properties of materials that are coupled together within the portable computing device, various thermal stresses can be generated during temperature cycling. A device can be potentially damaged or deformed as a result of the thermal stresses.
Therefore, it would be beneficial to provide a housing for a portable computing device that is aesthetically pleasing and lightweight, durable and yet environmentally friendly. It would also be beneficial to provide methods for assembling the portable computing device that meet the above conditions and perform satisfactorily during thermal cycling of the device.